Mixing
Why does “[\s\S]” not working in C++11's regex
I have the code below this:
#include <string>
#include <regex>
int main(int argc, char const *argv) {
std::string s = "_apple_";
std::regex r1("_(\s|\S)+_");
std::regex r2("_[\s\S]+_");
std::regex r3("_.+_");
std::regex r4("_[pale]+_");
std::smatch sm;
printf("r1:%d r2:%d r3:%d r4:%dn",
std::regex_match(s, sm, r1),
std::regex_match(s, sm, r2),
std::regex_match(s, sm, r3),
std::regex_match(s, sm, r4));
return 0;
}
output:r1:1 r2:0 r3:1 r4:1
I can not understand why r2 is not match?
My environment is:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin.
regex c++11
asked Nov 19 '18 at 13:34
user1927896
62
|
show 2 more comments
I have the code below this:
#include <string>
#include <regex>
int main(int argc, char const *argv) {
std::string s = "_apple_";
std::regex r1("_(\s|\S)+_");
std::regex r2("_[\s\S]+_");
std::regex r3("_.+_");
std::regex r4("_[pale]+_");
std::smatch sm;
printf("r1:%d r2:%d r3:%d r4:%dn",
std::regex_match(s, sm, r1),
std::regex_match(s, sm, r2),
std::regex_match(s, sm, r3),
std::regex_match(s, sm, r4));
return 0;
}
output:r1:1 r2:0 r3:1 r4:1
I can not understand why r2 is not match?
My environment is:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin.
regex c++11
asked Nov 19 '18 at 13:34
user1927896
62
Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
Then maybe shorthands likesandScannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.
– Tim Biegeleisen
Nov 19 '18 at 13:47
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
1
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24
|
show 2 more comments
I have the code below this:
#include <string>
#include <regex>
int main(int argc, char const *argv) {
std::string s = "_apple_";
std::regex r1("_(\s|\S)+_");
std::regex r2("_[\s\S]+_");
std::regex r3("_.+_");
std::regex r4("_[pale]+_");
std::smatch sm;
printf("r1:%d r2:%d r3:%d r4:%dn",
std::regex_match(s, sm, r1),
std::regex_match(s, sm, r2),
std::regex_match(s, sm, r3),
std::regex_match(s, sm, r4));
return 0;
}
output:r1:1 r2:0 r3:1 r4:1
I can not understand why r2 is not match?
My environment is:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin.
regex c++11
asked Nov 19 '18 at 13:34
user1927896
62
I have the code below this:
#include <string>
#include <regex>
int main(int argc, char const *argv) {
std::string s = "_apple_";
std::regex r1("_(\s|\S)+_");
std::regex r2("_[\s\S]+_");
std::regex r3("_.+_");
std::regex r4("_[pale]+_");
std::smatch sm;
printf("r1:%d r2:%d r3:%d r4:%dn",
std::regex_match(s, sm, r1),
std::regex_match(s, sm, r2),
std::regex_match(s, sm, r3),
std::regex_match(s, sm, r4));
return 0;
}
output:r1:1 r2:0 r3:1 r4:1
I can not understand why r2 is not match?
My environment is:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 10.0.0 (clang-1000.11.45.5)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin.
regex c++11
regex c++11
asked Nov 19 '18 at 13:34
user1927896
62
asked Nov 19 '18 at 13:34
user1927896
62
edited Nov 19 '18 at 13:51
asked Nov 19 '18 at 13:34
user1927896
62
asked Nov 19 '18 at 13:34
user1927896
62
asked Nov 19 '18 at 13:34
user1927896
62
62
Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
Then maybe shorthands likesandScannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.
– Tim Biegeleisen
Nov 19 '18 at 13:47
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
1
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24
|
show 2 more comments
Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
Then maybe shorthands likesandScannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.
– Tim Biegeleisen
Nov 19 '18 at 13:47
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
1
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24
Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
Then maybe shorthands like
s and S cannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.– Tim Biegeleisen
Nov 19 '18 at 13:47
Then maybe shorthands like
s and S cannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.– Tim Biegeleisen
Nov 19 '18 at 13:47
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
1
1
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24
|
show 2 more comments
1 Answer
1
active
oldest
votes
The clang regex flavor is POSIX ERE acc. to clang-format regex syntax reference. In POSIX bracket expressions, the usual regex escape sequences, like s, d, w, and even ], are not supported.
The [sS] is the same as [\sS], and matches a backslash, s and S chars.
However, in POSIX regex standard, . matches any chars including line break chars thus there is no need using [sS] workaround.
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
The clang regex flavor is POSIX ERE acc. to clang-format regex syntax reference. In POSIX bracket expressions, the usual regex escape sequences, like s, d, w, and even ], are not supported.
The [sS] is the same as [\sS], and matches a backslash, s and S chars.
However, in POSIX regex standard, . matches any chars including line break chars thus there is no need using [sS] workaround.
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
add a comment |
The clang regex flavor is POSIX ERE acc. to clang-format regex syntax reference. In POSIX bracket expressions, the usual regex escape sequences, like s, d, w, and even ], are not supported.
The [sS] is the same as [\sS], and matches a backslash, s and S chars.
However, in POSIX regex standard, . matches any chars including line break chars thus there is no need using [sS] workaround.
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
add a comment |
The clang regex flavor is POSIX ERE acc. to clang-format regex syntax reference. In POSIX bracket expressions, the usual regex escape sequences, like s, d, w, and even ], are not supported.
The [sS] is the same as [\sS], and matches a backslash, s and S chars.
However, in POSIX regex standard, . matches any chars including line break chars thus there is no need using [sS] workaround.
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
The clang regex flavor is POSIX ERE acc. to clang-format regex syntax reference. In POSIX bracket expressions, the usual regex escape sequences, like s, d, w, and even ], are not supported.
The [sS] is the same as [\sS], and matches a backslash, s and S chars.
However, in POSIX regex standard, . matches any chars including line break chars thus there is no need using [sS] workaround.
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
answered Nov 19 '18 at 21:50
Wiktor Stribiżew
308k16126202
308k16126202
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
add a comment |
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
but, on a online clang compiler, the code is working as expected. I am sorry i can not find the compiler as the same as my computer. On my computer, the compiler is Apple LLVM version 10.0.0 (clang-1000.11.45.5)
– user1927896
Nov 20 '18 at 2:04
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
@user1927896 Your is POSIX for sure judging by the behavior. Check here.
– Wiktor Stribiżew
Nov 20 '18 at 6:12
add a comment |
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Interesting. On a GCC compiler, your code is working as expected.
– Tim Biegeleisen
Nov 19 '18 at 13:40
but it does not work on my computer. Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 10.0.0 (clang-1000.11.45.5) Target: x86_64-apple-darwin17.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
– user1927896
Nov 19 '18 at 13:43
Then maybe shorthands like
sandScannot be used in character classes in your flavor of C++. In any case, your first regex given is a suitable workaround. But +1 to your good question.– Tim Biegeleisen
Nov 19 '18 at 13:47
I test the code on Mac, Ubuntu and Windows. It works as expected on Ubuntu and Windows. So I guess s and S cannot be used in character classes under Apple LLVM or it maybe a bug. I am not sure.
– user1927896
Nov 19 '18 at 14:19
1
yes, i agree with you. the issue is not the os. I guess the issue is compiler.
– user1927896
Nov 19 '18 at 14:24